About Optics & Photonics TopicsOSA Publishing developed the Optics and Photonics Topics to help organize its diverse content more accurately by topic area. This topic browser contains over 2400 terms and is organized in a three-level hierarchy. Read more.

Topics can be refined further in the search results. The Topic facet will reveal the high-level topics associated with the articles returned in the search results.

Abstract

InGaAs single photon avalanche detectors have previously been fabricated with a negative-feedback mechanism, which allows for free-running Geiger-mode operation and improves the signal noise. To reduce the dark count and improve the detection efficiency, zinc diffusion is necessary to define the p-i-n junction and separate the high-field region from any mesa surface. Here, we demonstrate the benefits of a simple Zn-diffused geometry, yielding 1550nm single-photon detection efficiencies of 20% with a dark count rate of 8 kHz at 140 K for a 22μm diameter device.

Figures (6)

Electric field contour plots of a simulated reversed bias p-i-n diode, at room temperature, with various diffusion patterns to form the p-region. The simulation is cylindrically symmetric about x = 0. (a) Multiple diffusion ring structure, demonstrating a larger areal fill factor of high field regions. All p-regions are electrically connected to form the anode. (b) Single p-well structure.

Band diagram of the self-quenching SPAD with an electron barrier, at equilibrium. In Geiger-mode, electrons generated by impact ionization in the p-i-n drift towards the cathode (InP substrate) and are temporarily stopped at the InAlAs/InP conduction band barrier, reducing the voltage across the multiplication region and quenching the avalanche pulse.

Effects of diffusion geometry and temperature on SPDE: single 10μm diffusion; 1.0μm/1.5μm (width/spacing) rings; 1.0μm/1.0μm rings; 1.5μm/1.5μm rings. The best performance was obtained with the 1.0μm/1.5μm rings structure. All devices with Zn-diffused rings show improved performance compared to the conventional single diffusion device. The frequency refers to the laser pulse rate.

Estimates of device recovery time. (a) Saturation effects on SPDE due to slow recovery time. The 1.0μm/1.5μm structure was tested at 140K with variable input laser rates, at a bias of 43.2V corresponding to 8kHz DCR. Single-photon detection efficiency is 20% at 100kHz or lower illumination rates. (b) Recovery time dependence on bias voltage, at 180K, from self-triggered dark counts. The breakdown voltage of the device is 42 V.